Alternating electric current rectifier of the selenium type



Patented July 31, '1945 UNITED STATES PATENT OFFICE ALTEBNATING ELECTRIC CURRENT RECTI- FIER OF THE SELENIUII ma Leslie Ernest Thompson and Alexander Jenkins, King's CroI, London, England, In, by meme assignments, to The Union Switch Mid Signal Company; Bwlaavale,

lvania oirennsy l'a., a corporation No Application January 19,1044, Se-

rial No. 518,888. In Great Britain October 19.

mainly of indium instead of the metals or alloys hitherto utilized.

A rectifier embodying the invention is found to possess important advantages, in particular the rectification ratio has a satisfactorily high value while the so-called. bottom-bend" characteristlc is relatively low.

In carrying the invention into practice, the counter-electrode may be constituted by a layer 2 cum. (cl. ins-see) The coimter-electrode may however, be formed in other ways for example by sprayins, volatilisins or sputtering.

The favourable characteristics of the improved rectifier above indicated may be still further increased by the addition oi relatively small quantitles of other metals or substances to the indium so that the counter-electrode is composed. for

. example, of an indium alloy or mixture containing however a preponderating proportion 0! indium and the invention may be varied in this and other respects without exceeding its scope.

Having now described our invention. what we claim as new and desire to secure by Letters Patent is: p V

1. An alternating electric current rectifier oi the selenium type described provided with a counof metallic indium applied to the selenium layer under considerable pressure. The suriace oi the metal must however, be as clean and iresh as possible and should preferably be cleaned in any suitable manner before being applied to the selenium layer.

ter-electrode composed of indium, tor the purpose specified.

,2. A rectifier comprising a base plate provided with a layer of selenium, and a counter-electrode composed oi a layer oi indium applied to the selenium layer under considerable preuure.

1m ERNEST THOMPSON. ALEXANDER JENKINS. 

